Bridge conditions in Iroquois County, Illinois
568 inventoried bridges · 83 rated poor · 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
Of the 568 Iroquois County bridges in the federal inventory, 83 carry a poor rating. That 14.6% share is roughly 2x the national average.
- 83 of the 568 bridges in Iroquois County, Illinois, are rated in poor condition (14.6%) in the 2025 National Bridge Inventory, as of .
- 258 bridges (45.4%) are rated good and 227 (40.0%) fair.
- The median Iroquois County bridge was built in 1983.
- The busiest poor-rated bridge is Fai-57 NB over Ic RR (built 1967), carrying about 9,050 vehicles a day.
Good 45.4% · Fair 40.0% · Poor 14.6% of 568 bridges
Bridges rated poor
Every bridge in the county with a poor rating, busiest first. Poor means a major component is rated 4 or lower on FHWA's 0-9 scale; it is a repair flag, not a closure notice.
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| Fai-57 NB over Ic RR | 1967 | 9,050 | Poor |
| Fai-57 SB over T.p. & W RR | 1967 | 9,050 | Poor |
| Fai-57 SB over West Second St | 1967 | 9,050 | Poor |
| Fai-57 NB over Prairie CR | 1967 | 9,050 | Poor |
| Fai-57 SB over Prairie Creek | 1967 | 9,050 | Poor |
| Fai-57 SB over Louis Creek | 1968 | 8,750 | Poor |
| Fai 57 NB over Louis Creek | 1968 | 8,750 | Poor |
| US 45-52 over Langan CR | 1952 | 3,650 | Poor |
| US 45 & US 52 over Prairie Creek | 1952 | 3,250 | Poor |
| Ill 1 over Little Beaver Creek | 1918 | 2,000 | Poor |
| US 52 over Pike Creek | 1928 | 1,700 | Poor |
| Fas-330 CH31 over Iroquois River | 1965 | 1,200 | Poor |
| Ill 54 over I 57 | 1967 | 1,150 | Poor |
| Fas 334 /C.H.9 over Fai 57 | 1968 | 1,050 | Poor |
| Ill 49 over Br Pigeon Creek | 1990 | 1,050 | Poor |
| Ill 49 over Shavetail Creek | 1927 | 1,000 | Poor |
| Fas 321 (ch 4) over I-57 | 1965 | 825 | Poor |
| Tr-290 over Pike Creek | 1965 | 825 | Poor |
| Ch 29 over I-57 | 1965 | 800 | Poor |
| Tr 14 over Trib Spring Creek | 1972 | 300 | Poor |
| Fas 323 Ch 40 over Possum Trot Ditch | 1938 | 300 | Poor |
| Danforth Rd Fas 33 over I-57 | 1967 | 200 | Poor |
| Tr 91 B over Pike Creek | 1958 | 200 | Poor |
| Fas 1343 Ch 41 over Branch Sugar Creek | 1959 | 175 | Poor |
| Tr-290 over Martinton Ditch #3 | 1959 | 175 | Poor |
| CH 47 / 1200 N Rd over Fai-57 | 1968 | 150 | Poor |
| Fas1335ch42 over Trib Little Mud CR | 1918 | 150 | Poor |
| Tr 2C over Hooper Branch | 1968 | 150 | Poor |
| Tr 339 over Pigeon CR | 1967 | 150 | Poor |
| Tr 55B over Martinton Dch No 3 | 1927 | 125 | Poor |
| Colfax St over Trib of Spring CR | 1900 | 125 | Poor |
| Tr 327 MFT108TR over Louis Creek | 1960 | 100 | Poor |
| Tr 327 over Louis Creek | 1966 | 100 | Poor |
| Tr 26A Mft 110 Tr over Louis Creek | 1916 | 75 | Poor |
| Tr 282 over Trib Sugar Creek | 1910 | 75 | Poor |
| Tr 140 over Trib Praire CR | 1962 | 75 | Poor |
| Tr 442 over Trib to Iroquois Rv | 1952 | 75 | Poor |
| Tr 104 over Trib Prairie Creek | 1976 | 75 | Poor |
| Tr 155 over Praire Creek | 1976 | 75 | Poor |
| Tr 84 over Br of Spring Creek | 1953 | 75 | Poor |
| Tr 359 over Trib to Pigeon CR | 1925 | 75 | Poor |
| Tr 280 over Trib. to Mud CR | 1971 | 75 | Poor |
| Tr 217 over Spring CR | 1965 | 75 | Poor |
| Tr 331A over Stream | 1976 | 75 | Poor |
| Tr 285 over Trib to Sugar Creek | 1983 | 75 | Poor |
| Tr 284 (old Rt 1) over Br Sugar Creek | 1930 | 50 | Poor |
| Tr 126 over Little Mud CR | 1970 | 50 | Poor |
| Tr 126 over Mud CR | 1954 | 50 | Poor |
| Tr 2 over Stream | 1959 | 50 | Poor |
| Tr 108 over Langan Creek | 1983 | 50 | Poor |
| Tr 41 over Langan Creek | 1985 | 50 | Poor |
| Tr 565 over Spring CR | 1915 | 50 | Poor |
| Tr 44A over Trib Langan Creek | 1956 | 50 | Poor |
| Tr 30 over W. Br Langan CR | 1965 | 50 | Poor |
| Tr 345B over Trib Little Mud Ck | 1920 | 50 | Poor |
| Tr 1 over Trib to Pigeon CR | 1981 | 50 | Poor |
| Tr 352 over Trib Mud CR | 1967 | 50 | Poor |
| Tr 2E over Stream | 1914 | 50 | Poor |
| Tr 396 over Trib to Sugar CR | 1907 | 50 | Poor |
| Tr 434 over Sugar CR | 1921 | 50 | Poor |
| Tr 2 D over Trib to Sugar CR | 1965 | 50 | Poor |
| Tr 317 over Unnamed Tributary | 1995 | 50 | Poor |
| Tr 1 over Fountain CR | 1958 | 50 | Poor |
| Tr 293 over Little Mud Creek | 1971 | 25 | Poor |
| Tr 22B over Louis Creek | 1964 | 25 | Poor |
| Tr 228 over Mud CR | 1914 | 25 | Poor |
| Tr 49 B over Prairie CR | 1904 | 25 | Poor |
| Tr 245 over Coon Creek | 1916 | 25 | Poor |
| Tr 276 over Coon Creek | 1916 | 25 | Poor |
| Tr 89 over Prairie CR | 1976 | 25 | Poor |
| Tr 135 over Praire Creek | 1924 | 25 | Poor |
| Tr 22 over Prairie CR | 1934 | 25 | Poor |
| Tr 94A over Trib. to Spring CR | 1928 | 25 | Poor |
| Tr 104 over Trib to Spring CR | 1956 | 25 | Poor |
| TR97 over Drainage Ditch | 1987 | 25 | Poor |
| Tr 341 over Gay Creek | 1967 | 25 | Poor |
| Tr 320 over Martinton Ditch #3 | 1955 | 25 | Poor |
| Tr 242 over Mud CR | 1917 | 25 | Poor |
| Tr 228 over Jefferson CR | 1910 | 25 | Poor |
| Tr 16 over Stream | 1964 | 25 | Poor |
| Tr 351 over Trib to Pigeon CR | 1961 | 25 | Poor |
| Tr 452 over Stream | 1977 | 25 | Poor |
| Tr 10B MFT120 over Louis Creek | 1962 | 20 | Poor |
Busiest bridges in the county
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| I-57 over Dranage Ditch | 2015 | 18,100 | Fair |
| I-57 over Dranage Ditch | 2015 | 18,100 | Fair |
| I-57 NB & SB over Prairie Creek | 2015 | 18,100 | Fair |
| Fai-57 over Stream | 1971 | 17,600 | Fair |
| I-57 SB over Langan Creek | 2013 | 9,550 | Fair |
| Fai-57 NB over Langan Creek | 2014 | 9,550 | Fair |
| Fai-57 NB over Fas 317 & Icg RR | 1966 | 9,200 | Fair |
| Fai-57 SB over Fas 317 & Icg RR | 1966 | 9,200 | Fair |
| Fai-57 SB over Ic RR | 1967 | 9,050 | Fair |
| Fai-57 NB over Ic RR | 1967 | 9,050 | Poor |
Source: FHWA National Bridge Inventory, 2025. Counts cover inventoried highway bridges over 20 feet; ratings are reported by the state DOT.
All of Illinois: Illinois bridge conditions by county · every download on the data page.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.